typesOfVariables.cpp

#include<bits/stdc++.h>
using namespace std;


int main() {
	/*
	1. Ordinary Variable:
	    --> A block gets created in the memory with name x, value 5 and some address(starting at base address)
	2. Pointer Variable:
	    --> Used to hold address of some other variable
	3. Reference Variable: (New in C++, was not in C)
	    --> It is a new name to an already existing variable
	    --> To be initialized at declaration only(with some previously created variable and not constant)
	    --> Contains reference of another variable
	    --> Reference variables cannot be updated
	    --> Modern style of pointer. It is an internal pointer


	IMP: Address will be used in context of pointers and reference will be used in case of reference variables
	*/
	cout << "Ordinary Variable:\n";
	int x = 3; // Ordinary Variable
	cout << "x: " << x << endl;

	cout << "\nPointer Variable:\n";
	int *p;   // Pointer Variable
	p = &x; // To be read as: p holds address(&) of x
	cout << "p (Address of x): " << p << endl;
	cout << "*p (Value at address of x): " << *p << endl;

	cout << "\nReference Variable:\n";
	int &y = x; // Reference Variable --> Reference of x is stored in y
	cout << "y (Value of x): " << y << endl;
	cout << "&y (Reference of x): " << &y << endl;

	assert(p == &y); // Value of address and reference for the same variable should be same;


	y++; // This increments the value of x

	cout << "\nAfter doing y++:\n";

	cout << "x: " << x << endl; // Value of x changes to 4

	cout << "y (Value of x): " << y << endl; // Value of y changes to 4
	cout << "&y (Reference of x): " << &y << endl;
}